Bacillus Cholerae Suis. 



HOG cholera; swine-plagub of Billings; schweinepest (Gerwi,); 



CHOIiBBA DU POEC, PNEtTMO-ENTEBITB (,Fr.). 



Origin. — In the blood, organs and intestinal contents of swine 

 that die of, hog cholera. 



Form. — Short, small rods, like those of chicken cholera. On some 

 media, as gelatin, it may form long rods. Occurs single or in pairs. 



Motility. — It is actively motile and has several long, wavy flag- 

 ella. Shows no motion in serum or in blood. 



Sporulation. — Not observed. 



Anilin dyes. — At first impart a bi-polar stain, but on sufficient 

 exposure the entire 'rod is colored. Not stained by Gram's method. 



Growth.— Is fairly rapid. 



Plates, — In a couple of days colonies develop on gelatin plates. The deep colonies 

 are very small, yellowish-brown and spherical. The surface colonies spread slightly. No 

 liquefaction. 



Stab culture, — Shows along the line of inoculation a white line or row of colonies, 

 while on the surface of the gelatin a thin, very slowly spreading growth forms. 



Streak culture,— Ovl agar forms a moist grayish-white growth, without any special 

 characteristics. On potato a straw-yellow growth develops, resembling somewhat that of 

 glanders. 



Bouillon,— DiSMSe cloudiness of the liquid; a partial film^orms on the surface. Indol 

 and phenol are not formed. Milk. — Is not coagulated. 



Oxygen requirements. — It is a facultative anaerobe. 



Temperature. — Grows well at ordinary temperature. Best at 37°. 



Behavior to gelatin. — Does not liquefy. 



Aerogenesis. — Glucose is fermented. 



Attenuation. — Arti;Qcial cultures retain their virulence quite 

 well. The virulence can be readily increased ',by repeated passage 

 through rabbits. It is then very fatal to pigeons. 



Immunity. — Can be produced experimentally by inoculation with 

 filtered cultures; with repeated small doses of blood, previously 

 heated to 54^58°, from infected rabbits (?). Blood serum of immun- 

 ized animals protects. 



Pathogenesis. — Hogs, mice, rabbits and guinea-pigs are highly 

 susceptible; pigeons are less susceptible, while chickens, sheep and 

 calves are immune. % c.c. of bouillon culture injected subcutane- 

 ously into rabbits kills in about four days. Bacilli distributed every- 

 where. White necrotic areas in the liver. Hemorrhagic infiltrations 

 are common. 



Infection.— Results through the food. The hog is the only ani- 

 mal that naturally contracts the disease. 



Diagnosis. — As a rule the bacillus can be isolated frpm the heart- 

 blood and organs. In chronic cases, because of secondary infection, 

 diverse bacteria may be present. Isolation may be facilitated by 

 • inoculating a rabbit with the suspected material. 



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